Calibrating for FB and RC paper In Ilford multigrade developer. I use a Durst M601
with colorhead but it is always on white light. I change grades with ilford filters. As is described i calibrated for speed first, but even the RC paper gets me values ranging from -14 to -26, in grades 2-5

JJ -

Sorry to hear you've been experiencing problems calibrating your Analyser. Using Ilford filters and paper together with a colour head should give you results that are fairly close, but there are a number of factors which can affect your results and offsets of up to a stop are not unusual. Enlarger lamps can and do vary and this can affect results particularly with VC paper. Also, the particular density you choose to calibrate to will affect the results significantly - in particular if you choose too bright a white you're getting into the toe area of the paper curve and large changes of exposure produce small changes on the paper (as you'll know if you've ever tried pre-flashing). We don't specify a precise density to set the white point to for two reasons - first, most people don't have a reflection densitometer and second, it gives you the choice to set the unit up how you want. If you like punchy prints for example you might want to choose a lighter white point and a darker black.

Ultimately, the Analyser is a print-making tool so you can set it up fairly closely by simply examining your prints. Use the built-in test strip generator to make a series of prints from one negative and choose the exposure that gives you the highlights you want. It's important to judge exposure by [color=darkred]highlights [/color] alone. If the best result is say 1/2 stop darker than the Analyser recommends, enter -6 in the cal table (the steps are 1/12 stop) for that paper grade. If after you've got the highlights right the shadows are too light or too dark, you can adjust the contrast settings to achieve the results you prefer. Use a smaller step size at the harder grades, and a larger one at the softer grades to minimise the effort involved.

If at the end of the day you need a large offset to get the results you want, that's perfectly fine, it doesn't indicate a fault either with the Analyser or with your other equipment or technique.

If you're still having difficulty by all means get in touch, we're always happy to help, and I'm sorry if we didn't provide the best response last time!